INCIDENCE OF HYPOPHOSPHATEMIA IN PATIENTS WITH SEVERE TRAUMATIC BRAIN INJURY AND ITS IMPACT ON MORTALITY: A RETROSPECTIVE STUDY

Background: Hypophosphatemia is a common electrolyte disturbance in critically ill patients, particularly those with severe traumatic brain injury(TBI).Phosphate plays essential roles in bone structure, cellular energy metabolism, membrane integrity, and acid-base balance. Despite its clinical relevance, data on the incidence, risk factors, and consequences of hypophosphatemia in TBI patients remain limited.

Methods: We conducted a retrospective observational study of patients with severe TBI admitted to a surgical intensive care unit (ICU). Serum phosphate levels were measured at ICU admission and at 72 hours. We evaluated the incidence of hypophosphatemia, its potential causes and its clinical consequences.

Results: Among 106 patients with severe TBI, hypophosphatemia occurred in 55.6% at ICU admission and persisted in 49% at 72 hours. Risk factors included insulin therapy,respiratory alkalosis, catecholamine administration, higher mannitol use, and greater illness severity. Hypophosphatemia was associated with longer mechanical ventilation, higher incidence of arrhythmias, and increased nosocomial infections. Importantly, hypophosphatemia remained an independent predictor of 28 day mortality after adjustment for confounding variables.